This invention relates to a bagging machine. More particularly, this invention relates to a bagging machine for particulate material. Still more particularly, this invention relates to a bagging machine for foamed loose-fill packaging elements.
Heretofore, various types of filling or bagging machines have been used for filling bags with particulate materials, such as foamed plastic packaging elements. For example, U.S. Pat. No. 6,035,606 describes a filling machine in which a bag is suspended within an opening of a conveyor from a plurality of upstanding posts. As the conveyor moves the bag past various stations, air is blown into the bag to open the bag, a flow of particulate material is delivered into the bag and then the bag is closed at the upper end while still suspended from the conveyor. In one embodiment, after a bag has been filled, a pair of pins are moved down into the plane of the bag and then moved away from each other to grasp opposite points of the bag and to pull the mouth of the bag closed. In addition, a heat seal device is actuated to heat seal the facing edges of the bag after the pins have spread the mouth of the bag. After the heat sealing operation has been performed, the pins are withdrawn from the bag so that the bag is free to drop onto a second conveyor for transport to a shipping or storage destination.
It is an object of the invention to improve the operation of a bagging machine for loose fill.
It is another object of the invention to automate the filling, sealing and removal of a series of filled bags from a bagging machine.
It is an object of the invention to provide an improved heat sealing arrangement for sealing bags which have been filled with material.
It is another object of the invention to provide a simple sealing means for sealing a bag in a bagging machine.
It is another object of the invention to facilitate the sealing and removal of a filled bag from a bagging machine.
It is another object of the invention to enhance the operation of an existing bagging machine.
Briefly, the invention provides a bagging machine which is comprised of a conveyor that has at least one opening for depending a bag therefrom and that moves past a bag mounting station at which a bag is suspended from the opening, a bag filling station at which the bag is filled, e.g. with particulate material, and a closing station at which the bag is closed.
In accordance with the invention, the conveyor is provided with a plurality of vertically disposed pins peripherally of the opening for receiving a folded over edge of a bag thereon. In addition, means are provided for moving a bag off at least two of the pins while other means are provided for moving two other pins laterally of the opening between a first position adjacent the opening with an open bag on the pins and a second retracted position spaced from the opening to close the bag disposed on these pins.
In an embodiment where four pins are used to suspend a bag from an opening of the conveyor, two of the pins are stationary and are disposed on opposite sides of the opening to receive the folded over edge of a bag. In addition, the means for moving a bag off each of these pins includes a plate disposed adjacent each stationary pin and a piston and cylinder arrangement for moving the plate between a lowered position under a bag on the pin and a raised position to move the bag off the pin.
The bagging machine is provided with a means for synchronizing movement of each pin and cylinder arrangement relative to the means for moving the movable pins laterally of the opening in the conveyor. In this respect, after a bag has been filled, the piston and cylinder arrangements are actuated to raise the respective plates to push the bag off the two stationary pins. Thereafter, the two movable pins are actuated to spread apart thereby closing the mouth of the bag on itself.
The bagging machine also includes sealing means, e.g. a heat sealing means, for sealing a bag suspended from the two movable pins in the spread apart position thereof. The heat sealing means includes a pair of heat seal bars and means for moving the heat seal bars into engagement with the closed bag in order to heat seal the bag in the closed position.
In accordance with the invention, the sealing means further includes a pair of rubber blocks, each of which is mounted on and projects beyond a respective heat seal bar in facing relation to the other rubber block for grasping a closed bag therebetween prior to heat sealing of the bag. In addition, the rubber blocks are spring mounted on the respective seal bars. The springs are compressible to allow each block to move relative to the respective seal bar in response to the blocks engaging each other. The spring mounting of the rubber blocks allows grasping of the upper end of the bag immediately prior to heat sealing and provides for a secure sealing of the two sides of the bag together.
The heat seal bars are reciprocally mounted within the machine and are driven via separate piston and cylinder units. In addition, an electric heater is electrically connected to each seal bar for heating thereof and a switch is disposed in the path of movement of one of the seal bars for sensing passage of the seal bar thereby. The switch is connected to the heater for actuating the heater in response to movement of the seal bars toward the other. This allows the heater to be actuated as an impulse heater only when necessary and only for a cycle, for example of 1.5 seconds or any other time which is suitable to heat seal the two sides of the bag together.
In accordance with the invention, a severing means is provided to sever the bag above or within the heat sealed area for purposes of removing the bag from the table. For example, a fly knife arrangement is used to sever the bag above the heat sealed area.
The bagging machine employs a station for delivering a flow of particulate material under gravity into a bag suspended from the conveyor. This station includes a hopper from which particulate material may be delivered downwardly to the conveyor and a sleeve disposed at the bottom of the chute in spaced relation to and above the conveyor and the pins thereon for directing the particulate material in the hopper into the opening in a bag. In accordance with the invention, an annular brush extends from the sleeve towards the conveyor to direct the particulate material into a bag suspended from the opening in the conveyor while sealing the flow of particulate material from the surrounding environment. The use of a brush allows the pins and other upstanding elements on the conveyor to pass through the brush without interference with the movement of the conveyor.